Nanomaterial dust is more explosion-prone that normal dust

In 2008, a sugar refinery in Portwentworth, Georgia exploded, killing 13 people and injuring 42 others.

The culprit was a dust explosion. That's the violent combustion
of extremely fine particles when they're suspended in an enclosed
location's air. Coal, wheat flour, cornstarch and other types of
dust can be hazardous in certain industries.

These sorts of explosions have been recorded since 1785, so we
now know quite a bit about the combustible properties of dust. But
dust, according to the US National Fire Protection Association
(NFPA), is defined as a finely divided solid with a diameter of
less than 420 μm -- those are micrometres. With the rise of nanomaterials, there's a new type of dust on the scene -- and
it's measured in the nanometre range.

Researchers from Dalhousie University in Halifax, in an study for the American Chemical Society's journal
Industrial & Engineering Chemistry Research, probed these
smaller "nontraditional" dusts to see how they compare to old
fashioned wheat and sugar.

They found that the energy needed to ignite nanomaterials made of
metals, such as aluminium, is less than 1 mJ -- that's less than
1/30th the amount of energy you'd need to make sugar dust explode,
or less than 1/60th of the energy required to set wheat dust
aflame.

They also mention the electrostatic flocking
process, which is where products and surfaces can be given a
tactile surface -- to increase friction and reduce reflectivity --
by attaching tiny fibres to materials. The process generates static
electricity, which could set off an explosion of flocculent
dust.

With this information under their belt, the researchers warn
that precautions should be taken to prevent nanomaterial dust from
exposure to sparks, collisions or friction, as it could quite
easily fuel an explosion.